Stoker feed mechanism



0% 1935- H. E. PRESTON STOKER FEED MECHANISM Filed Nov. 5, 1931 3 Sheets-Sheet 1 Oct. 29, 1935. H. E. PRESTON STOKER FEED MECHANISM Filed Nov. 5, 1951 3 Sheets-Sheet 2 Oct. 29, 1935- H. E. PRESTON STOKER FEED MECHANISM 3 Sheets-Sheet 5 Filed NOV. 5, 1951 Patented Oct. 29, 1935 STATES PATENT STOKER FEED MECHANISM Herbert E. Preston, Philadelphia, Pa., assignor to American Engineering Company, Philadelphia, Pa., a corporation of Pennsylvania 4 Claims.

This invention relates to improvements in stoker feed mechanism, and relates more particularly to improved means for feeding fuel to the main rams of a multiple retort underfeed stoker of the general character disclosed in U. S.

Patent No. 792,862.

A principal object of the invention is to pro- .vide novel and improved mechanism insuring a uniform and uninterrupted passage of fuel from the coal hopper or hoppers to the said rams.

A more specific object of the invention is to provide positive means for preventing arching of coal in the hoppers interfering with free and regular movements of the fuel to the rams.

The invention further resides in certain novel structural features and details hereinafter set forth and illustrated in the attached drawings, in which:

Figure 1 is a front elevational and partial sectional view of the hopper of a multiple retort underfeed stoker made in accordance with my invention; a

Fig. 2 is a side elevational and partial sectional view of the hopper;

Fig. 3 is a section on the line 33, Fig. 2, and

Fig. 4 is a section on the line 4-4, Fig. 1.

With reference to the drawings, the hopper therein disclosed comprises a vertical rear wall I which in assembly adjoins the front wall of the furnace, and upwardly and outwardly inclined front wall 2 and end walls 3 and 4. In the bottom, the hopper has a longitudinally extending series of openings 5 which respectively communicate with a corresponding series of ram cylinders 6, these cylinders being formed in castings l, to which the hopper is secured by means of bolts 8 and clamps 9 and ID. The cylinders 6 are located well below the floor of the hopper and are connected through the openings 5 by passages H formed in the said castings I. Rams (not shown) are adapted to operate within the cylinders 6 in well known manner to force the fuel passing into the ram cylinders into the upper ends of the stoker retorts, and the usual crank shaft I2 is across the bottom of the hopper between the front and rear walls and which has rear and front edges conforming respectively to the vertical and inclined rear and front walls of the hopper. The

members It which are in the form. in the present 5 instance of open brackets have each a base portion ll of substantial width which rest upon the respective wear plates 14, and each of said members has a central boss 18 having a transverse cylindrical opening for reception of a, shaft 19 which 10 extends longitudinally of the hopper and through the end walls 3 and 4, bearings 2|, 2| for said shaft being provided at the outer faces of said walls. Each of the members I6 is secured to the shaft by means of a pin 22 which extends through 15 the walls of the boss l8 and through holes in the shaft provided for their reception. The pins. 22 are tapered in the present instance and are held in place by cotter pins 23 passing through their lower projecting ends.

As shown in Fig. 4, each of the members It is formed in the present instance in two parts secured together by bolts 24, and in these two parts are formed the upper and lower halves of the boss l8 through which the shaft l9 extends. The 25 lower portion of the member I6 is provided front and rear with lugs 25 forming shoulders which underlie reverse shoulders on the front and rear walls of the hopper formed in the present instance by strips 26 suitably secured to the inner 30 faces of said walls. These interlocking shoulders prevent elevation of the members 16 from the wear plates l4 upon which they normally rest. From the upper portion of each of the members It extend arms 2'!- and 28, these arms respectively lying adjacent the rear and front walls of the hopper and in each case paralleling the adjacent wall. Each of these arms carries a pin 29 which are embraced respectively by the lower bifurcated ends of a pair of rods 3| and 32 respectively, thereby providing a slidable connection between the members l6 and rods 3| and 32.. The rods 3| and 32 extend upwardly parallel to the rear and front walls of the hopper, and adjacent their upper ends are pivotally connected to said walls through the medium of studs 33 projecting from the inner wall surfaces. The rods 31 and 32 as illustrated in Fig. 2 are somewhat spaced from the surfaces of the walls.

The opposite ends of the shaft l9 are connected respectively through links 34 and 35 with arms 36 and 31, and these arms are in turn respectively secured to shafts 38 and 39 supported in brackets GI and 42 on the end walls 3 and 4 of the hopper. To the lower end of each of the shafts 38 and. 39 5 is secured an arm, 43 and 44 respectively, each of which arms is suitably connected, through straps 45 and 46, with connecting rods 41 and 48. The other ends of these rods are connected respectively to crank pins 49 and 5| at the opposite ends of the shaft I2. The pins 49 and 5| lie at opposite sides of the axis of the shaft, so that with rotation of the latter they mutually contribute through the connecting rods and links to a longitudinal reciprocation of the shaft l9. Such reciprocation of the shaft l9 results in a corresponding reciprocation on the wear plates M of the members l6 and also in an oscillation of the rods 3| and 32 which as previously described are connected to said members. Each'of the connecting rods 41 and 48 is formedwith telescoping sections connected through the medium of a pin 52, this pin being adaptedto'. fracture under a predetermined stress. These .pins..con-. stitute safety elements preventing damage to any of the parts of the foregoing mechanism .dueto excessive strains developing from anycause.

In operation, coal or other.fuel;in the hopper passes by gravity through the openings 5 and passages H into the series of ram cylinders. The rams reciprocating in said, cylinders are withdrawn on the retractionstrokes to a point uncovering the lower ends. of the passages ll permitting the fuel to enter the cylinders, and in the forward stroke force this body of fuel from the cylinders into the upperends-of the stoker retorts. Each full reciprocation of the rams involves a similar reciprocation through the mechanism described above of the members i6 and a corresponding oscillation of the.-pivoted arms 3| and 32. This movement of the members l6 func-. tions to deliver the fuel transversely to the openings 5 and the upper ends of the passages-ll, thus eifectinga positive feed of the fuel to the ram cylinders and preventing any retardation of the feed due to arching of the fuel over the openings. Oscillation ofithe arms BI and 32 contributes towards maintaining a free movement of the fuel in the hopper to the ram cylinders, these arms having an-agitating effect preventing undue packing of the fuel in the hopperrwith a tendency to arch above the discharge openings 5.

It is apparent that the actuationof themembers l6 may be effected fromsother sourcesthan the crank shaft l2, and that there may be numerous changes in structural details without departure from the invention.

I claim:

1. A hopper having in the bottom a plurality of discharge openings through which the contents of the hopper are adapted to pass by gravity, a fiat horizontal bearing surface intermediate adjacent openings, a pusher slidably mounted on said surface, a bracket secured to said pusher and means operatively connected to said bracket for reciprocating said pusher transversely between the sides of said openings.

2. A hopper having in the bottom a plurality of discharge openings through which the contents of the hopper are adapted to pass by gravity, a flat horizontal bearing surface intermediate adjacent openings, a pusher slidably mounted on said surface, a'bracket secured to said pusher, means operatively connected to said bracket for reciprocating said pusher transversely between the sidesiof saidopenings, and guide means for retaining said pushers on said bearing surface.

3; A hopper having spaced side walls and a bottom'wall, aplurality ofidischarge openings in said bottom wall. through which the material in the hopper is adapted to'pass by gravity, a substantially fiat bearing surface intermediate adjacentopenings, a pusher slidably supported on said bearing surface, arms pivotally mounted adjacent the side walls .of the hopper; and having a slidable. connection with said pusher, and means for reciprocating said pusher transversely between the sides of saidopenings to agitate and positively feed the materialthereto, said movement'of the pushercausing-a swinging movement of said arms thereby effecting a further agitation of the material in the hopper.

4. A hopper having. spacedside walls and a bottom wall, a plurality of discharge openings in said bottom wall through which the material in the hopper is adapted to pass by gravity, a substantially fiat bearing surface intermediate adjacent openings, a pusherslidably. supported on each .of said bearing surfaces, a pair of arms extending upwardly along the side walls of the hopper from each of said pushers, and having a slidable connection with the latter, means for pivotally mounting said arms near the upper ends thereof, and means for. reciprocating said pushers to agitate and. positively feed the material to said. discharge openings, said movement of said pusher imparting a swinging movement to said arms thereby effecting a further agitation of the fuel in the hopper.

HERBERT E. PRESTON. 

